Infants and young children learn receptive (understood) language naturally through day to day interactions with their caregivers, typically their parents. An important component of this process is verbal labeling by the caregiver. For example, when a dog is in view, a parent might say “Look, that's a dog”. Parents and other caregivers also label items in picture books to infants by simply pointing at the picture and naming the object at which they are pointing. This type of interaction initially suffices to help the infant or child associate the word and the object. Generally, this type of learning process tends to be somewhat long as these sorts of interactions between caregiver and child occur interspersed throughout the day, as the adult has time and notices an object of interest to the child.
The language learning process is complicated by the fact that, in any given language, most words other than proper names chosen to be initially introduced to a child usually correspond not just to one particular object alone, but to a whole class of objects. For instance the word “dog” corresponds not just to one particular dog, but to a whole class of animals including Great Danes, Chihuahuas, and Poodles as well as toy dogs. Thus, conveying the idea of dog as a class of object requires a great many of these types of caregiver/child interactions.
The window for effectively learning any language well opens early in childhood but closes as the child grows older. In fact, most of an individual's native language is learned before the age of three. Children who have not learned a language well by this age may carry forward a serious learning handicap into adulthood. For the learning disabled, it is particularly crucial to take advantage of this period of time.
There are many materials and methods available for assisting parents and caregivers in educating their infants and young children in language learning but these materials and methods do not fully help a caregiver or parent maximize the learning window for language in infants and children. Language learning is a building process, and the mastery of one skill leads to the mastery of another. Thus, with infants and young children, time is of the essence in early intellectual development.